PORTER RANCH—The massive gas leak that took place last year in Porter Ranch is continuing to increase its cost deficit. The leak spewed dangerous methane gas for nearly four months and displaced 8,000 Porter Ranch families. Sempra Energy, a San Diego-based company, announced on Wednesday that the cost of this mishap is now at $665 million, more than double the original estimates taken by Southern California Gas Co. in February, as reported by ABC7.

The estimated costs of $250 million to $300 million in February came before the courts mandated the company to continue paying for residents living in temporary housing.

Residents of the Porter Ranch and surrounding San Fernando Valley suburbs were forced to leave their homes after growing cases of headaches, nausea, nosebleeds and other symptoms arose after they were exposed to the gas.

Southern California Gas Co. has reported that public health agencies have deemed the air quality in the area back to normal, however, thousands of residents are still leery about returning home until they are 100 percent certain that their homes are clean and safe.

The company has stated that it expects insurance to cover more than $1 billion in costs and it has accounted for $660 million in insurance receivables.

According to scientists, the gas leak at the Aliso Canyon storage facility that took place from October 23, 2015, until it was finally capped on February 18, 2016, was the largest-known release of climate-changing methane in U.S. history. It released an estimated 107,000 tons of methane into the air.